The National Weather Service issued a high fire danger alert for Cobb County and other counties in the region due to high winds.  The relative humidity is expected to remain above 25 percent, but sustained winds could spread any fires that do start.

What is in the statement?

The statement gives the following details:

…HIGH FIRE DANGER CONDITIONS THIS AFTERNOON INTO THE EVENING

FOR PARTS OF NORTH AND CENTRAL GEORGIA DUE TO STRONG WINDS…

Sustained winds of 15 to 25 MPH can be expected along with gusts

of 25 to 35 MPH. Some areas of high terrain may see gusts up to 50

MPH. Relative Humidities will likely stay above 25 percent,

though some locations in the northeast Georgia mountains may reach

critical minimum relative humidity thresholds for a few hours

this afternoon.

With dry fuels, high fire danger conditions can be expected.

Please refer to your local burn permitting authorities

whether you may burn outdoors.  If you do burn outside,

use extreme caution.

Why does low relative humidity increase the danger of fire?

The National Park Service published the following explanation of why low relative humidity increases the danger of fires:

“Relative humidity is important because dead forest fuels and the air are always exchanging moisture. Low humidity takes moisture from the fuels, and fuels in turn, take moisture from the air when the humidity is high. 

“Light fuels, such as grass and pine needles, gain and lose moisture quickly with changes in relative humidity. When the RH drops, fire behavior increases because these fine fuels become drier. 

“Heavy fuels, on the other hand, respond to humidity changes more slowly. To see significant changes in heavy fuel moisture, there must be significant moisture, usually from more than a single storm.”

What counties are affected?

The following counties are included in the hazardous weather outlook:

Banks, Barrow, Bartow, Carroll, Catoosa,…